The present invention relates to an improved apparatus for cracking nuts at high production rates.
In prior U.S. Pat. No. 4,418,617, there is disclosed a high production nutcracking apparatus wherein a plurality of cracking units are arranged on a rotatable turret, with each cracking unit having an opening adapted to receive an individual nut from a feed conveyor. Each cracking unit includes a mechanism for then cracking the nut as the turret continues to rotate, which is actuated by a pneumatic control system.
The feed conveyor as disclosed in the '617 patent includes a feed chain which comprises a plurality of nut transport elements which are mounted in succession, and with each nut transport element having an upwardly open receptacle for receiving an individual nut as it advances through a feed hopper. The feed chain extends in an upwardly inclined direction through the feed hopper and it is designed to feed the nuts from the hopper at a relatively high speed to the cracking units, while effectively orienting the nuts in the respective receptacles so that they may be engaged by the cracking units in an end to end orientation.
U.S. Pat. No. 5,623,867 discloses an improved nutcracking apparatus wherein the feed conveyor has an upper run which includes an upwardly inclined segment extending through the lower portion of the hopper and a horizontal segment extending from the upwardly inclined segment to the delivery or pick up point. To singulate and orient the nuts in the receptacle, there is provided a deflecting plate which overlies a portion of the upwardly inclined segment, and a brush located just downstream of the transition juncture to the horizontal segment.
When a machine as described in the '867 patent is run at very high speeds, such as 800 nuts per minute, the nuts tend to fly up from the transport elements, particularly at the arcuate transition juncture between the upwardly inclined segment and the horizontal segment. Also, the nuts tend to bounce during their transport, which upsets their orientation. The plate and brush as disclosed in the '867 patent have not proven to be satisfactory in consistently avoiding these problems.
A further limiting feature associated with the prior machine disclosed in the '867 patent, is the fact that the machine is not easily adaptable to accommodate nuts of differing sizes. Pecans, for example, vary significantly in size, and they are typically run through a sizing machine prior to cracking so as to separate the nuts into different grades. The machine of the prior patent is designed so that when the transport elements reach the pick up location, the sizing piston enters one end of the receptacle and moves the nut into engagement with an anvil at the other end of the receptacle. To properly grip the nut, it is important that the elevation of the sizing piston and anvil be aligned with the centerline of the nut. However, this does not always occur, since with pecans of small size, the sizing piston and anvil may be above the nut centerline, and in the case of large pecans they may be below the centerline. The prior machine has no easy way to accommodate these differences.
It is accordingly an object of the present invention to provide a high speed nutcracking apparatus which has a nut delivery system which is able to singulate and orient the nuts as they are removed from a hopper, and which is able to maintain their orientation until they are picked up by a cracking cylinder.
It is another object of the present invention to permit the nutcracking apparatus to be readily adjusted to accommodate nuts of differing sizes.